Expanding pulley



(No Model.)

3 Sheets-Sheet 1.

W. G. GASS.

EXPANDING PULLEY.

Patented Dec. 23, 1884.

3 Sheets-Sheet 2.

(No Model.)

W. G. GASS.

EXPANDING PULLEY.

No. 309,707. Patented D65. 23, 1884.

FIG.2

N, PETERS, Plmo-L lhvirnn starts Parent Unmet,

W'ILLIAM G. GASS, OF PHILADELPHIA, PENNSYLVANIA.

EXPANDING PULLEY.

:EPECIFICAI'ION forming part of Letters Patent No. 309,707, dated December 23, 1884.

Application filed October 13, 138i.

aZZ whom it may concern.-

Be it known that I, \VILLIAM G. Gitss, a subject of the Queen of Great Britain and Ireland, and a resident of Philadelphia, Pennsylvania, have invented certain Improvements in Expanding Pulleys, of which the following is a specification.

My invention relates to that class of expanding pulleys having a series of radially-adjustable segmental rim-plates, one of the objects of my invention being to so construct such a pulley that the expansion of the plates can be pulley; Fig. 5, Sheet 2, a detached. perspective i view of one of the segments of the rim; and

Figs. 6 and 7, Sheet 3, diagrams showing the extremes of expansion and contraction of the pulley.

A is a shaft, to which a uniform rotating motion is imparted in any suitable manner,

and to this shaft is secured, by a key or set- 5 screw, (shown by dotted lines in Fig. 1,) or in any other suitable manner, the frame of the pulley, this frame consisting of the opposite end plates, B and D, the latter having a projecting hub, I), bolted to the inner face of the plate .13, as shown in Fig. 1.

In each of the plates l and .l.) are formed a series of radial slots, (1, for the reception of llangcs b atthc opposite ends of aserics of segmental. plates, F, which are thus guided radially by the slots and are free to move from and toward the shaft A. Lugs c on the inner sides of the plates F are hung, by means of pins f,

to the long arms of a series of levers, G, the short arms of which are pivoted to links y, hung to the outer ends of arms ll, projecting from the outer face of the plate D, and each of said levers bears upon a wedge, J, fitting snuglyin a recess in a drum, K, the latter being secured to and turning with the shaft A, so that the wedges are thus caused to rotate I l l l i i l with the shaft, but are adjustable longitudt nally in respect to the same. The rear ends of the wedges J have radialprojeetions 72, carrying anti-friction rollers 2', and the longitudinal adjustment of said wedges is effected by the contact of these rollers with one or other of a pair of segmental plates, M M, bent at the outer ends, so as to form cams. These plates are carried by the forked end of a bar, E, which is connected to the shifting rods 7t, and the latter are operated either by hand or by a suitable cam.

Hung to the arms H are a series of levers, l, the outer arms, at, of which are weighted, the inner ends of the levers having lugs a bearing upon thelongarms of the levers G, so that as the centrifugal force tends to maintain the weighted arms 'of the levers radially in line with their pivots the lugs n are caused to depress the lovers G to the full extent, as shown in Fig. 1. 'When the parts are in the position shown in said ligure, the segmental plates F are ad j ustcd as closely possible to the shaft A, as shown in Fig. 7, and thus form the rim of a pulley ofsniall diameter; but if the wedges T are moved in the direction of the arrow, Fig. l, the lovers G and plates F will be thrust outward and the diameter of the pulley will be expanded, the limit of such expansion being shown in Fig. 6.

It will be observed on reference to Fig. 2 (in which the course of the belt is shown by dotted lines) that the cam-plates M M are 1i mited in extent, so that when one ofthe wedges J comes under the action. of plate M the rimplate F, controlled by said wedge, is on the in side of the pulley, and is free from the pressure of the bolt, the expansion of said rim-plate being thereby readily effected without any sudden or severe strain upon the camplate or its operating devices.

It should be understood that when the ex panded plate F strikes the belt and is subjected to pressure it has no tendency to move the wedge backward, as the pressure of the lever G upon the wedge is almost directly at right angles to the longitudinal movement of the latter. The retraction of the wedges is effected by the action of the cam-plate M upon the roller. 17 of the wedges. The series of wedges J are embraced bya pair of clamping:

ICO

rings, T, which resist any tendency to displacement of the wedges due to centrifugal iorce.

' The weighted levers P serve to counterbal ance the centrifugal force exerted upon the rim-plates F and levers G, and maintain said levers constantly in contact with the wedges, the deflection of the weighted arms of the levers P and the consequent pressure of the lugs or upon the levers G increasing in proportion to the increased centrifugal force exerted upon the levers and rim-plates asthe latter are expanded. For this reason the weighted levers are preferred, instead of springs, although,

where such acccurate counter-balancing is not necessary, springs may be used for depressing v the levers.

- plates, F, and a series of expanding wedges adjustable independently of each other, as set 2. The combination, in an expanding pulley, ofa shaft, a pulley-frame, a series of la dially-guidcd rim-plates, F, a series of independently-adjustable expanding wedges rotating with the shaft, and a'cam-plate constructed to act upon said wedges during aportion only of their rotation, as set forth.

3. The combination, in an expanding pulley, of the frame, the rim-plates F, radiallyguided therein, the levers G, and the independently-adjustable wedges J, as set forth.

4. The combination of the frame, the rimplates F, radially guided therein, the levers G, the links g, and the wedges J, as specified.

5. The combination of the frame, the rimplates F, radially guided therein, the levers G, the levers I, having weighted arms m, and the wedges J, as set forth.

6. The combination of the frame, the rim- 'plates F, radially guided therein, the indescribing witnesses.

VILLIAM G. GASS.

\Vitnesses:

J OHN M. CLAYTON, H ARRY SMITH. 

